7 Expert Tips for a Lush, Green Terrace Garden
A gardening expert gives insightful and essential steps on how to go about setting up a thriving rooftop garden
A serene garden in which one can unwind is high on the wishlist of every nature lover. However, many of us are restricted by the lack of space in cities. In such situations, a building’s terrace is the perfect place to set up your own private garden. Apart from providing refreshing access to greenery, rooftop gardens can also help maintain cooler temperatures in and around your home. Your terrace garden need not be restricted to a scattered collection of pots. With some practical know-how and creative thinking, you can transform your terrace into a lovely outdoor space for relaxation, with lawns, lighting, water bodies and beautiful shaded areas for seating. Here are expert insights on how to go about planning your terrace garden.
Expert tips by Sunil de Sousa, veteran agriculturist and director of Greenpiece
Expert tips by Sunil de Sousa, veteran agriculturist and director of Greenpiece
1. Check the load-bearing capacity of the roof slab
The first step is to determine if your roof slab is strong enough to handle the load of a terrace garden, including the weight of the soil, waterproofing systems, plants and seating. Sunil de Sousa recommends consulting a professional to accurately analyse your structural system and determine the right location for your rooftop garden. This will depend on the location of your load-bearing walls and columns. In some instances, such as in the case of a cantilevered roof, the slab can support less weight.
2. Essential pre-treatments
In any terrace garden, care must be taken to plan drainage points and prevent stagnation of water. Water stagnation and seepage can cause cracks in the roof slab and long-term structural damage. To prevent this, de Sousa says that the roof slab should be first treated with a layer of screed concrete (a thin layer of cement and sand or fine aggregate that makes a smooth, level surface for further treatments) and then waterproofed with a chemical compound like bitumen. If one is using planter boxes, these compounds can be applied to them before filling them with soil. For proper, efficient drainage, de Sousa recommends using a layer of PVC drainage cells, topped with a layer of geotextile fabric (a synthetic, absorbent gardening fabric). The soil is then poured on top of these two layers.
See more terrace garden designs from around the world
The first step is to determine if your roof slab is strong enough to handle the load of a terrace garden, including the weight of the soil, waterproofing systems, plants and seating. Sunil de Sousa recommends consulting a professional to accurately analyse your structural system and determine the right location for your rooftop garden. This will depend on the location of your load-bearing walls and columns. In some instances, such as in the case of a cantilevered roof, the slab can support less weight.
2. Essential pre-treatments
In any terrace garden, care must be taken to plan drainage points and prevent stagnation of water. Water stagnation and seepage can cause cracks in the roof slab and long-term structural damage. To prevent this, de Sousa says that the roof slab should be first treated with a layer of screed concrete (a thin layer of cement and sand or fine aggregate that makes a smooth, level surface for further treatments) and then waterproofed with a chemical compound like bitumen. If one is using planter boxes, these compounds can be applied to them before filling them with soil. For proper, efficient drainage, de Sousa recommends using a layer of PVC drainage cells, topped with a layer of geotextile fabric (a synthetic, absorbent gardening fabric). The soil is then poured on top of these two layers.
See more terrace garden designs from around the world
3. Get the right soil mixture
“The soil mixture for terrace gardens is slightly different from the one used for outdoor gardens, since the soil needs to promote drainage and be lightweight, as well,” de Sousa says. The soil needs to be a mix of soil conditioners, fertilisers and regular garden soil. Soil conditioners can be used to enhance water retention and help retain nutrients. One can also use silicon-based soil conditioners like vermiculite or organic options like coco peat and peat moss.
“The soil mixture for terrace gardens is slightly different from the one used for outdoor gardens, since the soil needs to promote drainage and be lightweight, as well,” de Sousa says. The soil needs to be a mix of soil conditioners, fertilisers and regular garden soil. Soil conditioners can be used to enhance water retention and help retain nutrients. One can also use silicon-based soil conditioners like vermiculite or organic options like coco peat and peat moss.
4. Choose the right type of plants
There should be an appropriate mix of flowering plants, ground cover and shrubs for your terrace garden. De Sousa says that common choices for Indian climates include the areca palm (Chrysalidocarpus lutescens), plumbago (Plumbaginaceae), bird of paradise (Strelitzia reginae), yellow trumpet bush (Tecoma gaudichaudi, T. castanifolia) and a variety of others – ask your local nursery what is best for your terrace. For ground cover, one can choose smaller types of verbena (Verbenaceae), monkey grass (Ophiopogon japonicus) and rain lily (Zephyranthes candida, white, and Z. rosea, pink) and many others.
If the roof slab can withstand the weight, you can even opt for medium-sized tropical trees, such as the Ashoka tree (Saraca asoka). For terraces which do not have adequate shelter from the sun, de Sousa suggests low-maintenance gardens without heat-sensitive plants.
More tips on planning a verdant terrace garden
There should be an appropriate mix of flowering plants, ground cover and shrubs for your terrace garden. De Sousa says that common choices for Indian climates include the areca palm (Chrysalidocarpus lutescens), plumbago (Plumbaginaceae), bird of paradise (Strelitzia reginae), yellow trumpet bush (Tecoma gaudichaudi, T. castanifolia) and a variety of others – ask your local nursery what is best for your terrace. For ground cover, one can choose smaller types of verbena (Verbenaceae), monkey grass (Ophiopogon japonicus) and rain lily (Zephyranthes candida, white, and Z. rosea, pink) and many others.
If the roof slab can withstand the weight, you can even opt for medium-sized tropical trees, such as the Ashoka tree (Saraca asoka). For terraces which do not have adequate shelter from the sun, de Sousa suggests low-maintenance gardens without heat-sensitive plants.
More tips on planning a verdant terrace garden
5. Plan the seating and other aesthetic elements
Incorporate seating in appropriate places to enjoy your terrace garden to the fullest. Here, the choice of material is important, since seaters on terrace gardens are exposed to the elements throughout the day. For warm and coastal Indian climates, Sunil recommends dressed stone seats, as they remain cool for the greater part of the day. For places with cooler climates, one can opt for seats made from materials like acacia wood, colloquially referred to as kikar wood.
Explore ideas for styling your terrace
Incorporate seating in appropriate places to enjoy your terrace garden to the fullest. Here, the choice of material is important, since seaters on terrace gardens are exposed to the elements throughout the day. For warm and coastal Indian climates, Sunil recommends dressed stone seats, as they remain cool for the greater part of the day. For places with cooler climates, one can opt for seats made from materials like acacia wood, colloquially referred to as kikar wood.
Explore ideas for styling your terrace
“The current trend in outdoor seating is to go for movable furniture made from all-weather materials like rattan,” de Sousa says. One can choose from a wide variety of commercially available tables, chairs and swings that are specially treated to withstand the elements.
Along with seating, garden ornaments and decorative elements can be used to lend an aesthetic touch to terrace gardens. “One can opt for ornaments like bird baths, stone urns and bird feeders,” de Sousa. Water ponds and fountains can also be installed to create a pleasing ambience in your terrace garden.
When it comes to outdoor lighting, Sunil says that LED lights are a popular option. Other viable options for terrace gardens are solar-powered lights. These have solar panels built into their fixtures. “The advantage of solar powered lights is that they don’t require wiring and are movable,” says Sunil. All pathways would require low, inset lighting. One can opt for footpath lights and mushroom fittings. Carved granite light fixtures are also in vogue.
He also recommends using uplighting techniques, where lights are installed at ground level and used to illuminate objects from below. “Focused uplighting for shrubs and trees can be used to create a fairytale-like feel in terrace gardens,.” de Sousa says.
More lighting ideas for outdoor spaces
More lighting ideas for outdoor spaces
7. After-care and maintenance
Prioritising maintenance is a crucial aspect of planning all roof gardens, de Sousa says. A full-fledged roof garden will need an irrigation system for regular maintenance. For a small garden, a simple sprinkler system would do. For larger gardens, Sunil recommends a combination of a drip and a sprinkler system. “Pump systems that can be activated from a convenient location within the house will simplify maintenance,” he says.
Plan for easy access points to the terrace, so that daily care and watering is not an issue. Other tips for planning a low-maintenance garden is to avoid planting too many annuals or lawn grasses that require a lot of watering and mowing.
Read more:
6 Mistakes to Avoid in Your Balcony Garden
Tell us:
What type of decorative elements would you like to use in your terrace garden? Tell us in Comments below.
Prioritising maintenance is a crucial aspect of planning all roof gardens, de Sousa says. A full-fledged roof garden will need an irrigation system for regular maintenance. For a small garden, a simple sprinkler system would do. For larger gardens, Sunil recommends a combination of a drip and a sprinkler system. “Pump systems that can be activated from a convenient location within the house will simplify maintenance,” he says.
Plan for easy access points to the terrace, so that daily care and watering is not an issue. Other tips for planning a low-maintenance garden is to avoid planting too many annuals or lawn grasses that require a lot of watering and mowing.
Read more:
6 Mistakes to Avoid in Your Balcony Garden
Tell us:
What type of decorative elements would you like to use in your terrace garden? Tell us in Comments below.
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